Calathar's Consuming Shield

You summon a shield to block a spell being cast at yourself or an ally within 60 feet of you. If the creature is casting a spell of 5th level or lower, the spell is consumed by the shield and you gain one spell slot of the consumed spells level. If it is casting a spell of 6th level or higher, make an ability check using your spellcasting ability. The DC equals 10 + the spell's level. On a success, the creature's spell is consumed, however you may only regain a spell slot equal to or below the level at which you cast the shield.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the spell is consumed and you gain one spell slot of the corresponding level.